Ports: Add Free Heroes of Might and Magic II (fheroes2) port

`fheroes2` is a recreation of HoMM2 game engine. This port is set with
`GET_HOMM2_DEMO=ON` for a free demo version to be automatically
downloaded and used, without requiring the user to provide game
resources from the original game.

Besides the provided patches, we set `CXXFLAGS="'-D_GNU_SOURCE'"` to
build the port, for SerenityOS' `LibC/endian.h` to provide required
endianness functions and constants.

**Considerations**:
* In-game custom cursor is not working, game logs show:
  `Cursors are not currently supported` [0].
* Game is still unplayable, as it commonly raises a Kernel panic when
  trying to start a new game (reported at SerenityOS/serenity#9401).

[0] ae3bc94772/src/events/SDL_mouse.c (L952)

Ports/AvailablePorts.md

@@ -41,6 +41,7 @@ Please make sure to keep this list up to date when adding and updating ports. :^
 | [`ed`](ed/)                            | GNU ed                                                          | 1.15                     | https://www.gnu.org/software/ed/                                               |
 | [`emu2`](emu2/)                        | emu2 DOS emulator                                               | 2021.01                  | https://github.com/dmsc/emu2                                                   |
 | [`epsilon`](epsilon/)                  | graphical calculator simulator                                  | 15.5.0                   | https://github.com/numworks/epsilon                                            |
+| [`fheroes2`](fheroes2/)                | Free Heroes of Might and Magic II                               | 0.9.13                   | https://github.com/ihhub/fheroes2                                              |
 | [`figlet`](figlet/)                    | FIGlet                                                          | 2.2.5                    | http://www.figlet.org/                                                         |
 | [`fio`](fio/)                          | fio - Flexible I/O tester                                       | 3.29                     | https://fio.readthedocs.io/en/latest/                                          |
 | [`flatbuffers`](flatbuffers/)          | Flatbuffers                                                     | 1.12.0                   | https://github.com/google/flatbuffers                                          |

Ports/fheroes2/package.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env -S bash ../.port_include.sh
+port=fheroes2
+useconfigure=true
+version=0.9.13
+depends=("SDL2" "SDL2_image" "SDL2_mixer" "libpng" "zlib")
+configopts=("-DCMAKE_TOOLCHAIN_FILE=${SERENITY_BUILD_DIR}/CMakeToolchain.txt" "-DUSE_SDL_VERSION=SDL2" "-DENABLE_IMAGE=ON" "-DGET_HOMM2_DEMO=ON")
+files="https://github.com/ihhub/fheroes2/archive/refs/tags/${version}.zip fheroes2-${version}.zip 879805bc88c3561d0eedc3dda425e8d9a3c7ae8a80b9f6909797acc72598cc17"
+auth_type=sha256
+launcher_name="Free Heroes of Might and Magic II"
+launcher_category=Games
+launcher_command=/opt/fheroes2/fheroes2
+icon_file=src/resources/fheroes2.ico
+
+pre_configure() {
+    export CXXFLAGS="'-D_GNU_SOURCE'"
+}
+
+configure() {
+    run cmake "${configopts[@]}" .
+}
+
+post_configure() {
+    unset CXXFLAGS
+}
+
+install() {
+    mkdir -p "${SERENITY_INSTALL_ROOT}/opt/fheroes2/files"
+    run cp -r data/ maps/ fheroes2 fheroes2.key "${SERENITY_INSTALL_ROOT}/opt/fheroes2"
+    run cp -r files/data "${SERENITY_INSTALL_ROOT}/opt/fheroes2/files"
+}

Ports/fheroes2/patches/ReadMe.md

@@ -0,0 +1,13 @@
+# Patches for fheroes2 on SerenityOS
+
+## `cmakelists.patch`
+
+Fix library detection for SDL2 dependencies in CMakeLists files.
+
+## `add-serenity-support.patch`
+
+Add `__serenity__` option in header files that validate current platform.
+
+## `set-sdl-software-renderer.patch`
+
+Use SDL Software renderer, instead of hardware-accelerated one.

Ports/fheroes2/patches/add-serenity-support.patch

@@ -0,0 +1,13 @@
+diff --git a/src/engine/endian_h2.h b/src/engine/endian_h2.h
+index 7d1fa275..84846ca9 100644
+--- a/src/engine/endian_h2.h
++++ b/src/engine/endian_h2.h
+@@ -21,7 +21,7 @@
+ #ifndef ENDIAN_H2_H
+ #define ENDIAN_H2_H
+
+-#if defined( __linux__ )
++#if defined( __linux__ ) || defined( __serenity__ )
+ #include <endian.h>
+
+ #elif defined( __FreeBSD__ ) || defined( __OpenBSD__ )

Ports/fheroes2/patches/cmakelists.patch

@@ -0,0 +1,55 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 87282647..ebed16ee 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -26,13 +26,16 @@ option(FHEROES2_STRICT_COMPILATION "Enable -Werror strict compilation" OFF)
+ #
+ # Library & feature detection
+ #
+-find_package(${USE_SDL_VERSION} REQUIRED)
+-find_package(${USE_SDL_VERSION}_mixer REQUIRED)
++INCLUDE(FindPkgConfig)
++
++PKG_SEARCH_MODULE(${USE_SDL_VERSION} REQUIRED sdl2)
++PKG_SEARCH_MODULE(${USE_SDL_VERSION}MIXER REQUIRED SDL2_mixer)
++
+ find_package(ZLIB REQUIRED)
+ find_package(Threads)
+
+ if(ENABLE_IMAGE)
+-	find_package(${USE_SDL_VERSION}_image REQUIRED)
++	PKG_SEARCH_MODULE(${USE_SDL_VERSION}IMAGE REQUIRED SDL2_image)
+ 	find_package(PNG REQUIRED)
+ endif(ENABLE_IMAGE)
+
+diff --git a/src/engine/CMakeLists.txt b/src/engine/CMakeLists.txt
+index 8a1fbeb3..b9df3120 100644
+--- a/src/engine/CMakeLists.txt
++++ b/src/engine/CMakeLists.txt
+@@ -5,19 +5,21 @@ target_compile_definitions(engine PRIVATE
+ 	$<$<BOOL:${ENABLE_IMAGE}>:FHEROES2_IMAGE_SUPPORT>
+ 	)
+ target_include_directories(engine PUBLIC
+-	$<$<BOOL:${ENABLE_IMAGE}>:${${USE_SDL_VERSION}_IMAGE_INCLUDE_DIR}>
+-	${${USE_SDL_VERSION}_MIXER_INCLUDE_DIR}
+-	${${USE_SDL_VERSION}_INCLUDE_DIR}
++	$<$<BOOL:${ENABLE_IMAGE}>:${${USE_SDL_VERSION}_IMAGE_INCLUDE_DIRS}>
++	${${USE_SDL_VERSION}_MIXER_INCLUDE_DIRS}
++	${${USE_SDL_VERSION}_INCLUDE_DIRS}
+ 	$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
+ 	$<INSTALL_INTERFACE:include>
+ 	)
+ target_link_libraries(engine
+ 	smacker
+-	${${USE_SDL_VERSION}MAIN_LIBRARY}
+-	${${USE_SDL_VERSION}_LIBRARY}
++	${${USE_SDL_VERSION}MAIN_LIBRARIES}
++	${${USE_SDL_VERSION}_LIBRARIES}
+ 	${${USE_SDL_VERSION}_MIXER_LIBRARIES}
+ 	$<$<BOOL:${ENABLE_IMAGE}>:${${USE_SDL_VERSION}_IMAGE_LIBRARIES}>
+ 	$<$<BOOL:${ENABLE_IMAGE}>:PNG::PNG>
++	$<$<BOOL:${ENABLE_IMAGE}>:-lSDL2_image>
++	-lSDL2_mixer
+ 	Threads::Threads # To match the build settings of the main app
+ 	ZLIB::ZLIB
+ 	)

Ports/fheroes2/patches/set-sdl-software-renderer.patch

@@ -0,0 +1,17 @@
+diff --git a/src/engine/screen.cpp b/src/engine/screen.cpp
+index 6083cb82..844ffb72 100644
+--- a/src/engine/screen.cpp
++++ b/src/engine/screen.cpp
+@@ -1003,10 +1003,10 @@ namespace
+         int renderFlags() const
+         {
+             if ( _isVSyncEnabled ) {
+-                return ( SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC );
++                return ( SDL_RENDERER_SOFTWARE | SDL_RENDERER_PRESENTVSYNC );
+             }
+ 
+-            return SDL_RENDERER_ACCELERATED;
++            return SDL_RENDERER_SOFTWARE;
+         }
+ 
+         void _createPalette()